Either play WITH them on the same faction, OR AGAINST them while in different factions. Ofc, unspoken agreements between 2 opposing factions can always take place when some egotistical, self-centered, unfortunate soul decides to attempt to bumrush your mobs in your grinding spot on a pvp map disrupting your respawn circuit and the productivity you would have had had the dumb SOB would've taken the time to recognize he had a whole map of mobs to work with that were yet unclaimed.

In this matter, having a friend on the opposing faction or a toon of your own on an alt. account in the opposing faction can prove to come in handy to regulate the NoobNess of those with a sense of false-pride for stealing your mobs when they realize all the sudden it might not be coinicidence that their "mighty" toon died soon after taking your mob circuit and making it a cluster**** of a respawn pattern.